Sprinkler system



Jan. 13, 1942.

c. F. TROOP SPRINKLER SYSTEM Filed March 51, 1939 INVENTOR cmuaJw E m mA YW B Patented Jan. 13, 1942 UNITED snares OFFICE SPRINKLER SYSTEMCharles F. Troop, Valencia, Pa.

Application March 31, 1939, Serial No. 265,233

2 Claims.

My invention relates to new and useful improvements in sprinkler systemsand fire extinguishment and more particularly to alarm means for use insuch a system to indicate that the system is in operation so as to warnindividuals that there is a fire.

An object of my invention is to provide an alarm unit having an alarmmeans and operating mechanism for controlling the same.

Another object is to provide a unit having an alarm means and which maybe inserted in the pipe line of the sprinkler system.

The invention consists in the novel cooperative relation and arrangementof parts, to be more fully described hereinafter and the novelty ofwhich will be particularly pointed out and distinctly claimed.

In the accompanying drawing, to be taken as a part of thisspecification, I have fully and clearly illustrated a preferredembodiment of my invention, in which drawing- The figure is a view of aportion of a sprinkler system showing the alarm unit, but with certaincasing cover members removed and certain parts in section for clarity ofillustration.

Referring to the drawing by characters of reference, I designatesgenerally a sprinkler system pipe line for water flow to the usual waterdischarge sprinkler head 2 closed by a fusible element 3 such that uponthe occurrence of fire sufiicient to raise the temperature of and fusethe element 3, the normally closed sprinkler head 2 will be opened todischarge water and put out the fire. Positioned in the pipe line I onthe inlet side of the sprinkler head 2, there is a water pipe 4 throughwhich all of the water flows to the sprinkler head 2 and which extendsthrough apertures in the end walls 5, 6 of a substantially rectangularmetal casing I. The pipe 4 has within the casing I a Venturi tubeportion 8 of converging-diverging bore providing a throat 9 for creatinga reduced pressure on flow of water through the pipe 4. Positionedwithin the casing 1 there is a differential pressure operated switch Isuch as is shown in the patent to Dillman, 2,088,556, July 2'7, 1937,having a substantially rectangular housing H which carries opposedpressure responsive power elements l2, 13, preferably of the bellowselement type, and which act in opposition to each other against the endsof an interposed thrust member I 4. The pressure responsive chamber ofthe power element I2 is communicatively connected by a fluid pressuretransmitting pipe or conduit 15 to the interior of the pipe 4 at thethroat 9, as at l6.

The pressure responsive chamber of the power element I 3 iscommunicatively connected by a fluid pressure transmitting pipe orconduit I! to the pipe 4 adjacent to and on the inlet side of theportion 8. The pipe I! also serves as a supporting means for the switchH1. The thrust member M which interconnects the power elements actsthrough a lever I8 pivoted at l8 to hold the switch arm l9 pivoted at l9normally in open position against the force of the switch closing spring26. The free end of lever IB which is pivoted at 26* to the thrustmember l4, bears on a cross pin 20 carried by the lever IS in order tohold the switch in open position as shown until a desired pressuredifferential exists as will be described. The switch arm l9 carries acontact member 2| which is cooperable with a contact member 22 to closea circuit between lead wires 23, 24 connected to terminal posts withinthe switch housing ll. Also positioned within the casing and secured tothe rear casing wall, there is a bell ringing transformer 25 having itsprimary terminals 26, 21 connected by lead wires 28, 29 respectively toa contact plug 30 secured in an opening through the casing end wall 5.Secured externally to the casing I and to the outside face of the rearcasing wall, there is an electrically energized alarm means 3| having abell 32 with a clapper 33 actuated by the usual electromagnet armature.The terminals 34, 35 of the alarm means are connected respectively tothe switch lead wire 24 and by a lead wire 36 to one terminal 31 of thetransformer secondary, the other transformer secondary terminal 38 beingconnected to the switch lead wire 23. The lead wires 24 and 36 extendthrough an aperture 39 in the rear wall of a casing 1. Also within thecasing I there is a closed stand pipe 40 connected into the pipe 4 onthe inlet side of the pressure transmitting pipe I! and serving as anair cushion to reduce the effects of water hammer and water surges onthe switch Ill.

The operation of my alarm unit is as follows: With the line I closedagainst discharge, the water pressure in the pipe 4 will act through thepipes l5 and I1 and be equal on the power elements l2 and I3 so that thethrust member I 4' will be positioned as shown with the switch in openposition. Any changes of head pressure in the system will be transmittedequally to the power elements 52 and I3 and therefore will not effectoperation of the switch. However, should the sprinkler head 2 be openedto discharge water, then flow will occur in the pipe ,4, resulting in areduced pressure at the throat 9 with a resultant reduced pressure ofthe power element l2 against thrust member l4. As soon as this reductionof pressure occurs, there will be an unbalance between power element 13and power element l2 so that the greater pressure exerted in and bypower element l3 will move the thrust member l4 upward or toward powerelement l2 and tending to move the free endpof lever l8 away from crosspin 20", thereby permitting spring 20 to rotate switch arm 19 and closecontact members 2| and 22. Closure of switch [0 at contact members 2|and 22 will complete the transformer secondary circuit, therebyenergizing the alarm means 3i to cause sounding of the alarm bell. It

should be noted that the rear wall of the casing 1 serves as a soundboard for the alarm means 3! as well as serving to support the alarmmeans and the transformer.

What I claim and desire to secure by Letters Patent of the United Statesis:

1. A unitary alarm device comprising a sheet metal supporting casing, anelectric alarm bell mounted exteriorly on a wall of said casing, a pipeextending through said casing thereby to support said casing, a casingwithin said first casing, switch means in said second casing andsupported by said pipe, and means operable to move said switch means toclosed position upon flow of liquid through said pipe, said switch meanscontrolling the circuit of said bell.

2. A unitary alarm device comprising a sheet material supporting casinghaving opposite wall apertures, a pipe extending through said aperturesthereby to support said casing, said pipe having a portion within saidcasing of converging-diverging bore providing a throat, a casing withinsaid first casing, a difierential pressure operated switch within saidsecond casing and having opposed pressure responsive elements positionedin said first casing, a conduit supporting said switch casing andconnecting one of said elements to said pipe adjacent said portion, aconduit connecting the other of said elements to said throat so thatupon flow through said pipe said switch will be closed, an electricallyenergized alarm bell having its circuit controlled by said switch, saidbell being carried by an external wall of said first casing such thatsaid first casing wall serves as a sounding board for said bell, atransformer in said first casing and having its secondary electricallyconnected to said switch and said bell, and a circuit terminal membercarried by a wall of said first casing and electrically connected to theprimary of said transformer.

CHARLES F. TROOP.

